/*
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *	  http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.jboss.el.lang;

import java.lang.reflect.Method;

import javax.el.FunctionMapper;

/**
 * @author Jacob Hookom [jacob@hookom.net]
 * @version $Change: 181177 $$DateTime: 2001/06/26 08:45:09 $$Author: markt $
 */
public class FunctionMapperFactory extends ExtendedFunctionMapper {

	protected FunctionMapperImpl memento = null;
	protected FunctionMapper target;
	
	public FunctionMapperFactory(FunctionMapper mapper) {
		if (mapper == null) {
			throw new NullPointerException("FunctionMapper target cannot be null");
		}
		this.target = mapper;
	}
   
	
	/* (non-Javadoc)
	 * @see javax.el.FunctionMapper#resolveFunction(java.lang.String, java.lang.String)
	 */
	public Method resolveFunction(String prefix, String localName) {
		if (this.memento == null) {
			this.memento = new FunctionMapperImpl();
		}
		Method m = this.target.resolveFunction(prefix, localName);
		if (m != null) {
			this.memento.addFunction(prefix, localName, m);
		}
		return m;
	}
	
	public Method resolveFunction(String prefix, String localName, int paramCount) {
	   if (this.memento == null) {
		   this.memento = new FunctionMapperImpl();
	   }
	   
	   Method m;
	   if (this.target instanceof ExtendedFunctionMapper)
	   {
		  m = ((ExtendedFunctionMapper) this.target).resolveFunction(prefix, localName, paramCount);
	   }
	   else
	   {	   
		  m = this.target.resolveFunction(prefix, localName);
	   }
	   
	   if (m != null) {
		   this.memento.addFunction(prefix, localName, m);
	   }
	   return m;
   }
	
	public FunctionMapper create() {
		return this.memento;
	}

}
